This application is a continuation-in-part of application Ser. No. 312,700, filed 21 Feb. 1989 which, in turn, in a continuation-in-part of application Ser. No. 175,947, filed 31 Mar. 1988, now abandoned.
This invention relates to facsimile transmission systems and methods for sending a document between a sender and a receiver by facsimile in a manner which prevents unauthorized casual reading of the document, and, more particularly, to an adhesive photocopyable transparency for use in a secure facsimile transmission system wherein one of two partial documents each containing portions of an original document which are complementary and mutually exclusive is photocopied onto the transparency and overlayed on the other of the two partial documents in registration therewith to recreate the original document, the transparency comprising, a rectangular sheet of a transparent plastic material having a surface for accepting and holding a photocopy image; an adhesive material disposed at an edge of the sheet of plastic material; and, a removable protective covering disposed over the adhesive material so as to allow the transparency to pass freely through a photocopy machine and be slid on the surface of a document without the adhesive material interfering therewith whereby after photocopying the one of two partial documents onto the transparency and placing it in registration on the other of the two partial documents the protective covering can be removed in situ to bond the transparency to the one of the two partial documents.
In above-referenced, co-pending '700 application, the teachings of which are incorporated herein by reference, a method and associated apparatus is disclosed by means of which a document can be transmitted between a sender and a receiver by facsimile in a manner which prevents unauthorized casual reading of the document. The method and an associated mechanical apparatus for practicing the method are shown in simplified form in FIGS. 1-5. As depicted in FIGS. 1 and 2, a pair of patterns 10 and 12 are alternately placed over the document 14 while it is scanned (either by a photocopy machine or the scanning head of a facsimile machine). Each pattern 10, 12 contains white portions 16 on a transparent background thus creating transparent portions 18. The patterns 10, 12 are complementary and mutually exclusive; that is, the "A" pattern 10 of FIG. 1 has white portions 16 where the "B" pattern 12 of FIG. 2 has transparent portions 18, and vice versa. Thus, when the document 14 of FIG. 3 is scanned through the "A" pattern 10 of FIG. 1 the partial document 14' of FIG. 4 is produced. Similarly, when the document 14 of FIG. 3 is scanned through the "B" pattern 12 of FIG. 2 the partial document 14" of FIG. 5 is produced. The two partial documents 14', 14" are then transmitted by facsimile to the receiver. At the receiving end, the two partial documents 14', 14" are difficult to read and understand, at least to the casual observer. As depicted in FIGS. 6 and 7, to "read" the original document the intended receiver makes a copy of one of the two partial documents, 14", on a transparency 20 and only has to place the transparency 20 over the other partial document, 14', in proper registration in order to view (and copy, if desired) the reconstructed document 14.
Without more, the transparency 20 and partial document 14' can come out of registration, which can be inconvenient for future use by the recipient.
Wherefore, it is the object of this invention to provide a photocopyable transparency for use with the method of the co-pending '700 application which eliminates the loss of registration problem and creates a bonded composite document for the recipient which is convenient to use for various purposes.
Other objects and benefits of this invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.